For example, Japanese Patent Application Publication Number 2008-4415 published on Jan. 10, 2008 discloses a light source assembly. This light source assembly has a polyhedron (a square frustum) having faces and LED elements mounted on top and lateral faces of the polyhedron, respectively. Each of the LED elements has anode and cathode electrodes which are electrically connected with conductive patterns formed on the top and lateral faces of the polyhedron through bumps.
In the light source assembly, it is necessary to put the LED elements on the top and lateral faces of the polyhedron, respectively. Therefore, dimensions and part cost of the light source assembly increase, and the work cost also increases by the increase of the mounting work.
Accordingly, if light sources including their own light emitting layers are mounted on the top and lateral faces of the polyhedron in place of the LED elements, the dimensions of the light source assembly can be reduced. However, by putting a light source on one face of the polyhedron, it is not possible to change all or a part of directions to emit light.